2016 Prius Transmission bolt sizes? Drain,fill

10mm

 

Yes....They are all 10mm. Toyota part number for the plug is 90341-18016.

 

Then, you are working on the wrong plug.

 

This should help:

 

Funnel with hose extension (roughly 3 foot) from above is easy. Trickiest part is just snaking the hose through. Keep a drip pan underneath, pour 3 quarts/liters quickly, then go 100 cc at a time, let it run through each time, till it starts dripping back out.

I read in some other document: the Toyota ATF WS shouldn't be kept long term, once opened. Not sure how critical it is, and before I read that I did use up some remainder from an earlier change. Still it's not a lot, maybe best to recycle the left over.

The pdf instructions to run the engine and recheck the level. At least with my third gen, I found no change, only did that the first time. Also, I think if you managed to put in roughly the spec amount (3.6 liter or 3.8 quarts), and the level is right at the lip of the fill hole, you're good.

 

Home Depot has 10mm 3/8 drive sockets for about $2-2.50.

 

Funnel from above is easier with a helper. They pour, you lie underneath, and at some point start screaming "StopStopStop...".

 

Interesting. I wonder why in step 2 (d) they say to reinstall the fill plug and old gasket and then in the next step, 3 (a), they say to remove the fill plug and gasket. Is that because they think you'll need a nap between draining & filling and don't want bugs to crawl in there?

Anyway, it does a good job of showing how simple the process is. I'll save the document for the torque specs since I plan to change mine after our vacation trip. Thanks, Mendel.

 

37 ft lbs is 10 pounds higher than the Gen3 ‘s torque spec.

Good to know.

 

Yeah, didn't notice that. There's no mention of the temporary reinstall of fill bolt in 3rd gen. Yeah maybe they really want to keep it closed up as much as possible? I've read in some TSB (which escapes me) that you should not use ATF WS from bottles that have been previously opened and then stored. Kinda like brake fluid I think.

Attached is third gen instruction, for your ref.

(2nd gen Repair Manual has no instruction for transaxle fluid change, btw.)

That I did notice, and my first thought: it's gonna be even MORE of a bear to break loose. Third gen is 29 ft/lb IIRC.

When you remember transaxle torque value, it's maybe a sign it's time to trade-in, lol?

Honda uses 3/8" square socket head cap screws for all these, btw. Not sure if it's superior, maybe less prone to rounding? It's certainly easer: just use a 3/8" drive ratchet (or 1/2" with reducer), with extensions as needed.